Problem: $ { \left[\begin{array}{rr}{-1} & {1} \\ {0} & {-1} \\ {-2} & {3}\end{array}\right]-\left[\begin{array}{rr}{-2} & {4} \\ {0} & {4} \\ {4} & {4}\end{array}\right] = {?} } $
To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{-1}-{-2} & {1}-{4} \\ {0}-{0} & {-1}-{4} \\ {-2}-{4} & {3}-{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{1} & {-3} \\ {0} & {-5} \\ {-6} & {-1}\end{array}\right]}$